Set up environment variables
Each app has its own Variables tab. Add keys one by one, or drop a .env / .txt file. There is no JSON import and no lock icon that turns a row into a Kubernetes Secret.
Add-on connection values are injected when you attach Postgres or Valkey. You do not paste those by hand unless you are restoring or switching instances.
Step by step
Open the app Variables tab
Open the app from the phase canvas, then Settings → Variables (Environment Variables).
Add a variable or import a .env file
Click Add variable, or use Drop or select a .env file. Only .env and .txt line formats are parsed. If a key already exists, the dashboard asks what to do with the overlap.
Save and redeploy if needed
Commit the change. A new revision picks up the variables. There is no “share this set across every app in the phase” control — copy keys per app, or attach the same add-on so injected URLs stay in sync.
Phases are separate
A variable on production is not copied to staging. Each phase has its own apps. Use the same key names and different values per phase.